1. Field of the Invention
This invention relates to dry forms of oxidant compositions, especially a dry form of dilute hypochlorite and hypochlorous acid compositions. The invention also relates to uses for these dry forms of oxidants, including generating hypochlorous acid vapor.
2. Description of the Related Art
U.S. Pat. No. 6,716,885 to Twydell et al., U.S. Pat. No. 5,342,597 to Tunison, III, U.S. Pat. No. 3,393,155 to Schutte et al. and U.S. Pat. No. 4,008,170 to Allan describe water dispersed in hydrophobic silica particles to give what is sometimes referred to as “dry water”. U.S. Pat. App. 2003/0160209 to Hoffman et al. describes the preparation of “dry oxone” from 1 N oxone solution and treated fumed silica. U.S. Pat. No. 6,569,353 to Giletto et al. describes a dual system of persulfate and oxidant in a sorbent material and an activator in a sorbent material, where the two gels are mixed together to give a material for decontaminating toxic agents. The sorbent material is selected from silicon dioxide, silica gel, silicon oxyhydroxides, aluminum oxide, alumina gel, aluminum oxyhydroxides, aluminates, other metal oxides, other metal oxyhydroxides, clay minerals and mixtures thereof, preferably, fumed silica. U.S. Pat. No. 3,730,789 to Mueller et al. describes rocket propellant formed by gelling aqueous oxidants with silica gel.
U.S. Pat. App. 2003/0156980 to Fischer et al. produced thickened solutions of 2.7-3% hypochlorite using fumed silica and optional additional thickeners. U.S. Pat. Appl. 2002/0179884 to Hoshino et al. found that dilute hypochlorite solutions create difficulties in obtaining a formulation with satisfactory storage stability.